Shoulder implant assembly

ABSTRACT

An implant assembly and associated method for selectively performing reverse and traditional arthroplasty for a shoulder joint that includes a humerus and a glenoid. The implant assembly may include a head, a cup, a humeral stem and an adaptor. The method includes inserting the humeral stem to the humerus and connecting a male taper of the adaptor to a female taper of the head. For reverse arthroplasty, the method includes attaching the adaptor to the glenoid and the cup to the stem. For traditional arthroplasty, the method includes attaching the adaptor to the humeral stem and the cup to the glenoid. The method also includes articulating the head with the cup.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/269,772 filed on Oct. 10, 2011 and issued Mar. 15, 2016 as U.S. Pat.No. 9,283,083, which is a division of U.S. patent application Ser. No.12/390,652 filed on Feb. 23, 2009 and issued Dec. 6, 2011 as U.S. Pat.No. 8,070,820, which is a continuation-in-part application of U.S.patent application Ser. No. 11/234,743 filed on Sep. 23, 2005 and issuedNov. 22, 2011 as U.S. Pat. No. 8,062,376, which is acontinuation-in-part of U.S. patent application Ser. No. 10/680,924filed on Oct. 8, 2003 and issued Feb. 13, 2007 as U.S. Pat. No.7,175,663. The disclosure of the above applications is incorporatedherein by reference.

FIELD OF THE INVENTION

The present invention relates to an implant assembly for shoulder jointreplacement.

BACKGROUND OF THE INVENTION

A natural shoulder joint may undergo degenerative changes caused by avariety of reasons. When these degenerative changes become so faradvanced and irreversible, it may ultimately become necessary to replacea natural shoulder joint with a prosthetic shoulder joint. In thetraditional implantation of a shoulder joint prosthesis, the naturalhead portion of the humerus is resected and a cavity is created in theintramedullary canal of the host humerus for accepting a humeralcomponent. The humeral component generally includes a stem and a headportion, which is used to replace the natural head of the humerus. Oncethe humeral component has been implanted, the glenoid cavity positionedat the scapula may also be resected and shaped to accept a glenoidcomponent. The glenoid component generally includes an articulatingsurface or cup which is engaged by the head portion of the humeralcomponent. Modular designs for the humeral and glenoid components arecurrently available for the traditional shoulder arthroplasty, andcomponents of different sizes or shapes are at the disposal of thesurgeon performing the operation.

The traditional shoulder joint arthroplasty typically involves thecoupling of a humeral head with a modified humerus, while a concavebearing member can be placed on a prepared glenoid. In the reverseshoulder prosthesis, the humeral component includes a stem and a cupconnected to the stem. The glenoid component supports a head whicharticulates with the cup.

It is not always practical to determine well in advance of the procedurewhether a reverse or traditional shoulder prosthesis should be used. Itis, therefore, desirable to provide a selection of modular componentsthat can be combined for use in traditional as well as reverse shoulderarthroplasty, with the goals of increasing flexibility and choice andfor providing interchangeable and easy to use components that are alsocost effective.

SUMMARY OF THE INVENTION

One embodiment of the invention provides an implant assembly for ashoulder joint that has a humerus and a glenoid. The implant assemblymay include a humeral stem configured to be inserted in the humerus, anda head bounded by a convex surface and a planar base that has a femaletaper. The implant assembly also includes an adaptor having a tray and amale taper. The tray may be configured to he attached to the glenoid.The male taper of the adaptor is configured to be received in the femaletaper of the head. The implant assembly also includes a cup that can beattached to the stem. The cup has a concave surface that is configuredto articulate with the convex surface of the head.

Another embodiment of the invention provides an assembly of implantcomponents for a shoulder joint having a humerus and a glenoid. Theassembly includes a humeral stem, a head having a convex surface, and acup configured to articulate with the convex surface of the head. Theassembly optionally includes a glenoid adaptor for a reverse shoulderarthroplasty, and a humeral adaptor for traditional shoulderarthroplasty. The glenoid adaptor is configured to connect the head tothe glenoid when the cup is connected to the humeral stem. The optionalhumeral adaptor is configured to connect the head to the humeral stemwhen the cup is connected to the glenoid. The same adaptor may be usedas a glenoid and as a humeral adaptor.

Another embodiment of the invention provides an assembly of implantcomponents for a shoulder joint having a humerus and a glenoid. Theassembly includes a plurality of humeral stems, a plurality of heads,and a plurality of cups configured to articulate with the heads. Theassembly also includes a plurality of glenoid adaptors for a reverseshoulder arthroplasty, and a plurality of humeral adaptors fortraditional shoulder arthroplasty. The humeral or glenoid adaptors havean offset feature which allows for relative positioning of the humeralor glenoid articulating surfaces. Each glenoid adaptor is configured toconnect one of the heads to the glenoid when one of the cups isconnected to one of the humeral stems. Each humeral adaptor isconfigured to connect one of the heads to one of the humeral stems whenone of the cups is connected to the glenoid.

Another embodiment provides a method for selectively performing reverseand traditional arthroplasty for a shoulder joint that includes ahumerus and a glenoid. The method includes providing a head, a cup, anda humeral stem. The method also includes providing a humeral adaptor fortraditional arthroplasty, and providing a glenoid adaptor for reversearthroplasty. Further, the method includes selecting one of the humeraland glenoid adaptors, and performing the corresponding arthroplastyutilizing the head, the cup, the humeral stem and the selected adaptor.

Another embodiment provides a method for selectively performing reverseand traditional arthroplasty for a shoulder joint that includes ahumerus and a glenoid. The method includes inserting a humeral stem tothe humerus and connecting an adaptor to a head with mating male andfemale tapers. The method also includes selectively attaching a base ofthe adaptor to the glenoid for reverse arthroplasty and to the stem fortraditional arthroplasty, and selectively attaching a cup to the stemfor reverse arthroplasty, and to the glenoid for traditionalarthroplasty. Further, the method includes articulating the head withthe cup.

Further areas of applicability of the present invention will becomeapparent from the detailed description provided hereinafter. It shouldbe understood that the detailed description and specific examples, whileindicating current embodiments of the invention, are intended forpurposes of illustration only and are not intended to limit the scope ofthe invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description and the accompanying drawings. The components inthe drawings are not necessarily to scale, emphasis instead being placedupon illustrating the principles of the invention.

FIG. 1 is an exploded view of an embodiment of an implant assemblyaccording to the invention, shown in a traditional shoulderarthroplasty;

FIG. 2 is an exploded view of an embodiment of an implant assemblyaccording to the invention, shown in a reverse shoulder arthroplasty;

FIGS. 3A-3D are side views of embodiments of an adaptor according to thepresent invention;

FIGS. 4A-4E are side views of embodiments of a cup according to thepresent invention;

FIG. 5A is an exploded view of an embodiment of an implant assemblyaccording to the invention, shown in a traditional shoulder arthroplastyand with alternative heads and humeral adaptors;

FIG. 5B is an exploded view of an embodiment of an implant assemblyaccording to the invention, shown in a reverse shoulder arthroplasty;

FIG. 6A is an exploded view of an embodiment of an implant assemblyaccording to the invention, shown in a traditional shoulderarthroplasty;

FIG. 6B is an exploded view of an embodiment of an implant assemblyaccording to the invention, shown in a reverse shoulder arthroplasty;

FIG. 7 is an exploded view of an embodiment of an implant assemblyaccording to the invention, shown in a reverse shoulder arthroplasty;

FIG. 8 is an embodiment of a assembly of components for shoulderarthroplasty according to the invention;

FIGS. 9A-9C are side views of embodiments of heads according to theinvention;

FIGS. 10A-10C are side views of embodiments of adaptors corresponding tothe heads of FIGS. 9A-9C;

FIGS. 11A-11C are side views of embodiments of head bearings;

FIG. 12 is an exploded view of an embodiment of an implant assemblyaccording to the invention, shown in a traditional shoulderarthroplasty;

FIG. 13 is an exploded view of an embodiment of an implant assemblyaccording to the invention, shown in a traditional shoulder arthroplastywithout a humeral stern;

FIG. 14 is an exploded view of an embodiment of an implant assemblyaccording to the invention, shown in a reverse shoulder arthroplastywithout a humeral stem;

FIG. 15 is an exploded view of an embodiment of modular adaptor, shownwith glenoid and humeral stems;

FIG. 16 is an exploded view of an embodiment of modular adaptor; shownwith glenoid and humeral sterns;

FIG. 17 represents a perspective exploded view of an alternate shoulderprosthetic;

FIGS. 18A-18C represent side views of the shoulder prosthetic shown inFIG. 17;

FIGS. 19A and 19B represent side views of an alternate shoulderassembly;

FIGS. 20A and 20B represent side views of an alternate shoulderassembly;

FIGS. 21A and 21B represent side views of an alternate shoulderassembly;

FIGS. 22A and 22B represent side views of an alternate shoulderassembly;

FIGS. 23A and 23B depict the assembly of a humeral component shown inthe joint prosthetic shown in FIGS. 20A and 20B;

FIGS. 24A-26B represent views of the glenoid component shown in FIGS.17-21B;

FIGS. 27A-29B represent bearings used in the assemblies shown in FIGS.18A, 18B, 20A and 20B;

FIGS. 30A-32 represent head components shown in FIGS. 17-22B;

FIGS. 33A-33C represent the adaptor shown in FIGS. 17-23B;

FIG. 34 represents a kit of components shown in FIGS. 17-33;

FIG. 35 represents the humeral implant for a reverse shoulderprosthetic;

FIGS. 36-40 represent an implant shown in FIG. 35 utilizing an alternatehead;

FIGS. 41A-41D represent glenoid fixation components;

FIGS. 42A and 42B represent a humeral body portion shown in FIGS. 35-40.

FIG. 43 represents a coupling glenoid tray according to the presentteachings;

FIGS. 44A and 44B represent the insertion of the tray shown in FIG. 43;

FIG. 45 represents a cross-sectional view of an implanted tray shown inFIG. 43;

FIG. 46 represents the coupling of an articulating head to the trayshown in FIG. 45;

FIG. 47 represents the coupling of a glenoid prosthetic to the trayshown in FIG. 45;

FIGS. 48 and 49 represent an alternate method to fix the tray of FIG. 43to a prepared glenoid;

FIGS. 50 and 51 represent alternate mechanisms to couple a head to thetray of FIG. 43;

FIG. 52 represents an alternate method of implanting the tray shown inFIG. 43;

FIG. 53 represents an exploded view of a prosthetic shoulder assembly;and

FIG. 54 represent an alternate shoulder prosthesis.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description of the preferred embodiments of the inventionis merely exemplary in nature and is in no way intended to limit theinvention, its application, or uses.

Referring to FIGS. 1 and 2, there is shown an embodiment of an implantassembly 100 for a total shoulder joint replacement. The implantassembly 100 is configured to be implanted between a resected humerus102 and a glenoid cavity (“glenoid”) 104 of a scapula 106 in one of twoways, i.e., in a traditional arthroplasty depicted in FIG. 1, or in areverse arthroplasty depicted in FIG. 2, by selecting and/orreconfiguring appropriately the components of the implant assembly 100.The implant assembly 100 includes a head 108, a cup 110, and an adaptor112. The implant assembly 100 may also include a humeral stem 114 thathas a proximal end 115 and a distal end 117.

Other embodiments of the implant assembly are shown in FIGS. 5A, 6A, 12,and 13 for traditional shoulder replacement, and in FIGS. 5B, 6B, 7 and14 for reverse shoulder replacement. FIGS. 3A-3D, 4A-4E, 9A-9C, 10A-10C,and 11A-11C show representative embodiments of various components. FIGS.15 and 16 show embodiments of a modular adaptor 113. FIG. 8 shows anembodiment of a component assembly (kit) for shoulder replacement 800showing different sizes of representative components. It should beunderstood that the component assembly 800 in FIG. 8 is onlyillustrative of the inclusion of different sizes of each component andit is not limited by the type of components actually shown. For example,the component assembly 800 may include different sizes of each of theheads 108 shown in FIGS. 9A-9C, different types and sizes of adaptors112, different sizes and types of cups 110, etc. Like reference numeralsrefer to like components. When clarity requires differentiating betweendifferent embodiments of the same component, an alphabetic character isattached to the reference numeral. For example, the head 108 isreferenced as head 108A and head 108B to distinguish between twodifferent head embodiments, as shown in FIG. 5A.

In the embodiment shown in FIGS. 1 and 2, the head 108 is bounded by aconvex surface 116, which may be, for example, a hemispherical surface,and a base 118, which may be a substantially planar surface. In oneembodiment, the base 118 may be modularly connected to the head 108. Afemale taper 120 with tapered inner walls 122 extends from the base 118into the head 108. The convex surface 116 of the head 108 is shaped toarticulate with a concave surface 124 of the cup 110 to allow forshoulder joint movement. Such articulation may be centered or eccentric.This and other embodiments of the head 108 are shown in FIGS. 9A-9C. Inthe embodiment of FIG. 9A, the head 108 has a male taper 140. In theembodiment of FIG. 9B, the head 108 has a female taper 142.

Referring to FIGS. 1 and 2, the cup 110 may include a back surface 126that may be configured to be selectively attached to the humeral stem114 in reverse shoulder arthroplasty, or to the resected glenoid 104 inthe traditional shoulder arthroplasty. Alternatively, the cup 110 may bechosen from a number for available cups, such as those shown in FIGS.4A-4D, some of which are better suited to either reverse shoulderarthroplasty or traditional shoulder arthroplasty. For example, the backsurface 126 of the cup 110 may be a substantially planar surface whichcan be attached with cement or with mechanical fasteners, such asscrews, to the humeral stem 114 or to the appropriately resected glenoid104. Alternatively, as shown in FIG. 4C, the back surface 126 may beslightly convex. In the embodiment shown in FIG. 4B, the back surface126 may include a number of pegs 127 for attachment to the glenoid 104.In the embodiment shown in FIG. 4D, the cup 110 may include a male taper121 which is received in a corresponding female taper 123 of theproximal end 115 of the humeral stem 114. FIG. 4E shows a bearing 192 ofa modular cup 110 that has a concave surface 124 and a female taper 144adapted to receive a modular glenoid stem 130 or modular humeral stem136, such as those shown in FIGS. 15 and 16 in connection with themodular adaptor 113. The bearing 192 may also be used with theembodiments of FIGS. 13 and 14, as is described below.

Referring to FIGS. 15 and 16, the modular adaptor 113 may include a body150 with a male taper 152 and a female taper 154. The female taper 154is adapted to receive a glenoid stem 134 for the reverse shoulderarthroplasty and a humeral stem 136 for the traditional shoulderarthroplasty. The male taper 152 is adapted to be received in the femaletaper 142 of the embodiment of the head 108 shown in FIG. 9B or in thefemale taper 120 of the embodiment of the head 108 shown in FIG. 9C, forexample.

In general, the adaptor 112 may be modular, such as the adaptor 113 ofFIGS. 15 and 16, or a monolithic adaptor. The adaptor 112 may be asingle, one and the same, adaptor that can be used selectively in boththe traditional and the reverse shoulder arthroplasty, or it can bechosen from a number of available adaptors of an assembly of components,such as those shown in FIGS. 3A-3D, depending on which arthroplastyprocedure is to be performed. Some of these adaptors 112, such as, forexample, the adaptor shown in FIG. 3C, may be specifically configuredfor use with reverse arthroplasty, because they incorporate the glenoidstem 134, either modularly or monolithically.

In one embodiment, the adaptor 112 may include an adaptor tray 128 andan extension or male taper 130 that can be press-fitted into the femaletaper 120 of the head 108. For the procedure of traditional shoulderarthroplasty, the tray 128 is attached to the proximal end of thehumeral stem 114, as shown in FIG. 1. For the procedure of reversearthroplasty, the tray 128 is attached to the glenoid 104, as shown inFIG. 2 in the embodiments of FIGS. 3A and 3C, the tray 128 may include acurved portion 132 shaped to conform to a portion of the glenoid 104. Itmay also include the glenoid stern 134, which is inserted into theglenoid 104. The adaptor may be attached to the glenoid 104 withfasteners, such as screws.

Referring to the embodiment of FIG. 3A, the tray 128 may also besubstantially planar. It will be appreciated, however, that othershapes, in addition to those shown in FIGS. 3A-3D, are possible for thetray 128 depending, for example, on the various ways the tray 128 is beattached to the humerus 102, to the humeral stem 114, or to the glenoid104. Furthermore, the adaptor 112 may be modular, such that the maletaper 130, the tray 128 and the glenoid stem 134 are all separatecomponents interconnected though fasteners, such as screws, or othertype of connectors, including male-female tapers as illustrated in FIGS.15 and 16. The adaptors 112, 112A shown in FIGS. 3D and 5A include amale taper 148 which can be received in the female taper of 120 of thehead 108, 108A, and a male taper 160 which can be received in the femaletaper 123 of the humeral stem 114.

In the embodiments illustrated in FIGS. 5B and 7, the cup 110 may bereplaced by a bearing base 170, which is also an adaptor, and a bearing172 that can be fitted to the base 170. The bearing base 170 has a maletaper 174 configured to be received in the female taper 123 of thehumeral stem 114. Examples of bearings 172 with symmetric ornon-symmetric and eccentric bearing surfaces 176 are shown in FIGS.11A-11C. in the embodiment of FIG. 7, the bearing base 170, includes afemale taper 178 adapted to receive the male taper 140 of the head 108B.

In the embodiment of FIG. 12, the cup 110 may be replaced by a bearing180 that is fitted in a bearing base 182 with mating male taper 184 andfemale taper 186, or with a bearing 180 that includes only a liner 188.The bearing base 182 may include a modular or integral glenoid stem 190.

Referring to FIGS. 1 and 2, for example, the implant assembly 100 may beused as follows. The humeral stem 114 is inserted in the resectedhumerus 102. The adaptor 112 is attached to the head 108 by insertingthe male taper 130 into the female taper 120. For traditional shoulderarthroplasty, the cup 110 is attached to the glenoid 104, and theadaptor 112 is attached. to the proximal end 115 of the humeral stem114, such that the convex surface 116 of head 108 articulates with theconcave surface 124 of the cup 110. For reverse shoulder arthroplasty,the cup 110 is attached to the proximal end 115 of the stem humeral 114and the adaptor 112 is attached to the resected glenoid 104 such thatthe convex surface 116 of head 108 articulates with the concave surface124 of the cup 110. Although the same adaptor 112 can be used for boththe traditional and the reverse shoulder arthroplasty procedures,glenoid-specific adaptors 112 may be chosen, either as integralcomponents or built from modular parts that include male tapers 130,trays 128 and glenoid stems 134.

It will be appreciated that the individual components of the implantassembly 100 may be made using a variety of materials, including metaland plastic. The head and the stem may be made of metallic material,such as a cobalt chrome alloy, for example. Porous coating may beprovided for the proximal end of the stem. The cup may be made ofpolyethylene or metal or a combination thereof, such as polyethylenebearing or lining and metal base. The adaptor can be typically made ofmetal.

Other exemplary embodiments are illustrated in FIGS. 5A, 5B, 6A, 6B, 7,and 12-14. In FIG. 5A, the male taper 140 of the head 108B can also beinserted directly into the female taper 123 of the humeral stem 123.Alternatively, an adaptor 112B having a male taper 162 and a femaletaper 164 may be provided. The adaptor 112B may be also used in theembodiments shown in FIGS. 5B, 6A, and 6B.

In the embodiments of FIGS. 13 and 14, the male taper 148 of the adaptor112A can be received in the female taper 120 of the head 108 for thetraditional shoulder arthroplasty shown in FIG. 13, and in the femaletaper 144 of the bearing 192 for the reverse arthroplasty shown in FIG.14. Similarly, the male taper 130 of the glenoid adaptor 112 may bereceived in the female taper 120 of the head 108 for the reverseshoulder arthroplasty, and in the female taper 144 of the bearing 192for the traditional shoulder arthroplasty.

FIG. 17 represents a perspective exploded view of an alternate shoulderprosthetic 200. The prosthetic 200 has a humeral stein 202 which ismated to a bearing 208 that interfaces with a head portion 210. The headportion 210 is coupled to a prepared glenoid 214. The humeral stem 202has a coupling portion 204 which is configured to mate with a couplingtaper 206′ on adaptor 206. The adaptor 206 has a coupling taper or taperlock connection 207 which is configured to couple to a correspondingcoupling taper 211 disposed on a surface of the bearing 208. The bearing208 has a bearing surface 209 which articulates with the articulatingsurface of the head 210.

FIGS. 18A and 18B represent a side view of the prosthetic 200 shown inFIG. 17. A second adaptor 206 is disposed between head 210 and theglenoid component 212. The adaptor 206 is configured to interface with acoupling taper 222 defined within the glenoid bearing member 212. It isenvisioned the coupling taper 222 can be either a male or a female taperlock connection configured to mate with an appropriate taper on the head210 (see FIG. 18C).

As shown in FIG. 18B, the glenoid bearing member 212 is coupled to theprepared glenoid 214 using a plurality of fixation screws 216. Theadaptors 206 optionally can have a pair of locking tapered members whichare off axis from each other, allowing a physician to rotate the offsetto align the components within the joint to increase the range of motionof the prosthetic 200. In this regard, the rotation of the adaptors 206allows for the radial, rotational and angular positioning of the headand cup members. Further it is envisioned that optionally, at least someof the components can be used in a traditional arthroplasty.

As shown in FIGS. 19A and 19B, the bearing member 208′ can be coupleddirectly to the coupling portion 204 of the humeral stem 202. In thisregard, the bearing 208′ can have a male coupled taper 206 or a femalecoupling taper. As shown in FIG. 19B, the use of an adaptor 206 havingan offset tapered stem can allow for relative movement of thearticulating head 210 with respect to the bearing 208.

As shown in FIGS. 20A and 20B, the articulating head 210 can have a stem213 which is configured to couple with a female locking taper 222 withinthe glenoid component 212. The use of an offset adaptor 206 locatedbetween the bearing 208 and the coupling portion 204 of the humeral stem202 allows for relative displacement of the bearing surface 209 of thebearing member 208 with respect to the head portion 210. Furthermore, byremoving the adaptor 206, the size of the joint can be reduced.

As shown in FIGS. 21A and 21B, the bearing 208 can be directly coupledto a coupling portion 204 of the stem 202. Additionally, the head 210can be coupled directly to the glenoid component 212 to reduce theoverall size of the joint. The direct coupling of the components isaccomplished by using locking tapers or fixation members such asthreaded fasteners or adhesive.

As shown in FIGS. 22A and 22B, a head 218 can be directly coupled to theglenoid 214. This head 218 can be directly coupled to the glenoid 214using a plurality of bone fixation screws 216 coupled to the head 218.Additionally, an attachment tray (not shown) can be used to couple thehead to the prepared glenoid. The bearing surface 219 of the head 218can have a varying radius of curvature over its surface. In this regard,the radius of curvature can be specifically design to interface with thebearing surface 209 of the bearing member 208 to increase the range ofmotion while reducing chances of dislocation of the joint.

FIGS. 23A and 23B represent the coupling of the bearing member to thehumeral component 202. The adaptor 206 is coupled to coupling portion204 of the stem, this regard, a male taper lock connection 226 isdisposed within the coupling portion 204. The bearing 208 is thencoupled to a male taper lock connection 228 disposed on the adaptor 226.A trialing adaptor 206 can be used to allow the placement of the bearingmember 208. In this regard, the trailing head is non-fixably coupled tothe stem and rotated to place the cup in its proper location. At thispoint, a regular adaptor 206 is fixably coupled the stem using animpactor as is known.

FIGS. 24A-26B represent alternate views of the glenoid member 212. Theglenoid member 212 has a first curved coupling surface 230 which isconfigured to be mated to a curved surface on the prepared glenoid 214.Additionally, the glenoid 212 has a outward facing surface 232 which isgenerally opposite to the coupling surface 230. Disposed on the outwardsurface 232 is a boss portion 236 which defines an exterior fixationtaper. Additionally, the boss 236 defines the interior taper 222 whichis configured to fixedly accept a male taper of the adaptor 206. Definedthrough the glenoid component is a plurality of bone fixation holes 234.The bone fixation holes 234 are angled with respect to each other toprovide enhanced fixation of the glenoid member 212 to the preparedglenoid 214.

FIGS. 27A-29B represent alternate bearing members 208. Disposed on acoupling surface 238 is the coupling taper 240. The coupling taper 240is configured to be mated either with an adaptor 206 or with the humeralfixation member 204. Defined on a bearing side 239 of the adaptor 208 isthe bearing surface 209. The bearing surface 209 can vary in curvatureto maximize the articulation of the head on the bearing surface 208while minimizing the possibility of dislocation of the head 210 from thebearing 208. As shown in FIGS. 28A and 28B, the surface 209 can have aprofile which varies with respect to the bearing side 239 or thecoupling surface 238.

FIGS. 30A-32 represent alternate heads 210 that can optionally be usedin the shoulder prosthetic 200. Disposed on a coupling side of the head210 is a fixation member 248 which can be a female or male couplingtaper. As shown in FIG. 32, the head 210 can further have an extendedarticulating surface 250 which can vary in radius of curvature and inlength.

FIGS. 33A-33C represent adaptors 206 having varying offsets foradjusting the location of the head or bearing member within the joint.It is envisioned the adaptors 206 additionally can have varying heightswhich allow for varying displacement of the head from the glenoid. FIG.34 represents the kit of bearing, head, and adaptor members utilized toconstruct the humeral prosthetic. It is envisioned that this kit canadditionally have varying stems and fixation devices such as screws.

FIG. 35 represents an alternate reverse humeral prosthetic 260 for usewith a large segment humeral resection. The modular humeral prosthetic260 has a humeral body portion 262, abase member 264, and a fixationstern 266. Optionally, the base member can annularly support a softtissue fixation member 268. The humeral body portion 262 has a concavebearing surface 270 configured to articulate with a head member in areverse shoulder. It is envisioned that this concave bearing surface 270can be a biocompatible polymer, metal or ceramic. The concave bearingcan be coupled to a modular bearing head 290 which is mated with acoupling taper 292 defined in the humeral body portion 262.

FIGS. 36-38 depict a side view of an implanted humeral prosthetic 260.Each humeral prosthetic 260 is mated with ahead 272 that is coupled tothe prepared glenoid 214. As shown in FIG. 36, the head 272 of thereverse shoulder prosthetic can be coupled to the prepared glenoid 214using a large mating screw 294. Additionally, the head 272 can haveextended articulating surface 274 to allow for proper articulation ofthe joint. As FIGS. 36 and 37 represent, the head 272 can have acoupling surface 215 which is generally perpendicular or angled to thefixation screw 294.

FIGS. 38 and 39 represent the coupling of the head portion 272 of theprosthetic to the glenoid 214. Shown is the tray 276 which is insertedinto an aperture 277 defined within a coupled glenoid 288. Next, afixation screw is used to couple the tray 276 to the prepared glenoid288. A head 272 is oriented and then snapped or fixed to the tray 276.

As shown in FIGS. 41B-41D, the tray 276 has a retaining flange 284 and abone screw accepting aperture 280. Disposed on a coupling surface of thetray 276 is a non-threaded extended region 286 which measures in lengthgreater than 6 millimeters. It has been found that having the extendedportion 286 having a length of greater than 6 millimeters allows for theproper coupling of the tray 276 without stress concentration failures inthe mating fastener. As shown in FIGS. 41A and 41B, the extended portion286 can have a counter bore 287, which is configured to accept a head ofthe bone engaging fastener 282.

FIGS. 42A and 42B represent the humeral body portion 262. As previouslymentioned, the humeral body portion 262 has a concave bearing member272. The concave bearing member 272 can be integral with the monolithichumeral body portion 262 or may be coupled to a bearing member 290. Inthis regard, the bearing member 290 can be coupled to a fixation member294 within the humeral body portion 262. The humeral body portion 262further has a locking member 292 which can either be a male or femaletaper to couple the humeral body portion 62 to the base member 264.

FIG. 43 represents an alternate tray 300 of the present teachings. Shownis a central fixation screw 302 configured to mate with a centralfixation hole 304 defined in a tray plate 306. The central fixationscrew 302 has a threaded body 308 having a bone engaging tip 310 andassociated coupling screw thread 312. As described below, the screw 302further has a head 314 configured to be removably coupled to a traycentral screw bearing surface 335. Included radially about the centralfixation hole 304 are a plurality of bone screw accepting apertures 316.In this regard, four bone screw accepting apertures 316 can have taperedinner surfaces 317 which are defined about the central fixation hole304.

The screw accepting apertures 316 are configured to optionally acceptcortical bone engaging screws 320. The cortical bone engaging screws 320can have a conical thread exterior surface 322. Associated with theconical exterior surface 322 can be conical heads 324 which areconfigured to engage a conical inner surface 317 of the screw acceptingapertures 316.

The plate tray 306 has a bone engaging surface 326 having a hollowtapered peg 328. As detailed below, the peg 328 defines a through bore330 linearly aligned with the central fixation hole 304. The tapered peg328 can have an exterior treatment to enhance the coupling of thehollowed tapered peg 328 with a prepared glenoid 331.

FIGS. 44A and 44B depict the coupling of a tray 300 to a preparedglenoid. As shown in FIG. 44A, an aperture 329 is formed in the preparedglenoid to receive the peg 328. At this point, the tray 300 can berotated to position the apertures 316 in locations where the bone tissueis most advantageous for coupling of the critical bone screws.

After positioning the peg 328 of the tray 300 in the bore 330, thecentral fixation screw 302 is passed through the central fixation hole304 and through the through bore 330 of the hollowed tapered peg 328.

As best seen in FIG. 45, the hollow tapered peg 328 has a first portion332 having a first exterior surface with a first diameter and a secondportion 333 having a second diameter smaller than the first diameter.The through bore 330 includes a seat portion 335 configured to functionas a bearing surface for engagement with the head 314 of the centralscrew 302. The location of the seated portion 335 is preferably locatedabout 6 millimeters from the coupling surface 334 of the tray 300. Thisoffset is configured to reduce bending moments and loading on thefixation screw 302. The through bore 330 further includes a couplinginterior taper 337 which is configured to engagably receive acorresponding fixation taper 338.

After fixation of the central screw 302, optionally, the plurality ofbone engaging screws 320 can be inserted into the bone screw acceptingapertures 316. In this regard, the tapered head surfaces 324 of the boneengaging screws 320 can engage the tapered inner surfaces of the bonescrew accepting apertures 316. The center lines of the plurality of bonescrew accepting apertures 316 may be parallel to the center line of thethrough bore 330. Additionally, the center line of bone acceptingapertures 316 can intersect or skew with respect to the centerline ofthe through bore 330. As seen in FIGS. 46 and 47, the head 324 orglenoid component 326 can have a male coupling taper 338. The head 324and glenoid component 326 can have a polymer, ceramic or biocompatiblemetal articulating surface disposed on a metal support.

As best seen in FIGS. 48 and 49, optionally the tray 300 can be coupledto the prepared glenoid using only the plurality of bone engaging screws320. In this regard, it is envisioned that the central fixation screws302 may not be used. In circumstances where the central fixation screwis not to be used, the peg 328 can be solid. Further, the plate can takethe form of the plate 170 of FIG. 5 having a plurality of bone screwaccepting apertures 316. As shown in FIGS. 50 and 51, a couplingmechanism 330 can be positioned between the head 324 and the tray 300.Optionally, the head 332 can have a countersink 334 configured toencapsulate the tray 300 to place the articulating head 324 close to theresected glenoid.

As shown in FIG. 52, the glenoid surface can have a countersink 336which can encapsulate the plate 306 of tray 300. As shown in FIG. 53,the adaptor 340 can be used to offset a head with respect to the centralscrew member 302. It is envisioned that this offset adaptor 340 can beused with either a head 324, as shown, or a glenoid component (notshown) to perform either a reverse or regular total shoulderreplacement. In this regard, during implantation, any of theaforementioned methods can be used to position a head at the scapula ora cup member. Additionally, previously detailed offsetting intermediatemembers can be used to change the positions of any of the articulatingmembers within a joint.

As shown in FIG. 54, a humeral stem 114 can be placed within themedullary canal of a humerus 102. As previously described above, coupledto the female taper 123 of the humeral stem 114 can be the base 170 withcorresponding female coupling taper 178. Disposed about a periphery ofthe coupling taper 178 can be at least one screw accepting aperture 316which accepts a bone engaging screw or fastener 320. Either thebaseplate 170 or the screw accepting aperture 316 can define a fastenerhead engaging surface. In this regard, after the humeral stem 114 is setinto the medullary canal of the humerus 102, the base 170 can he coupledto the female taper 123. Prior to fixably coupling the base 170 to thestem 114, the base 170 can be rotated into position so as to maximizethe retention by the bone fixation fastener 320. Fasteners 320 can thenbe selectively coupled to bone which is radially disposed about thecoupling portion 3432 of the stem 114.

While the invention has been described in the specification andillustrated in the drawings with reference to a preferred embodiment, itwill be understood by those skilled in the art that various changes maybe made and equivalents may be substituted for elements thereof withoutdeparting from the scope of the invention as defined in the claims. Inaddition, many modifications may be made to adapt a particular situationor material to the teachings of the invention without departing from theessential scope thereof. Therefore, it is intended that the inventionnot be limited to the particular embodiments illustrated by the drawingsand described. in the specification as the best modes presentlycontemplated for carrying out this invention, but that the inventionwill include any embodiments falling within the foregoing descriptionand the appended claims.

What is claimed is:
 1. An assembly of implant components for a shoulderjoint having a humerus and a glenoid, the assembly comprising: a headhaving a convex surface; a cup configured to articulate with the convexsurface of the head; a humeral stem; and a glenoid adaptor configured toconnect the head to the glenoid when the cup is connected to the humeralstem, and the glenoid adaptor further configured to connect the cup tothe glenoid when the head is connected to the humerus, said glenoidadaptor having a coupling peg defining a through bore, said through boredefining a coupling taper and a central screw bearing surface.